1. Field of the Invention
The invention relates to a drainage chamber for collecting body fluids, in particular liquor, with a collecting area limited by an outer wall for collecting the body fluid and with an inlet connection linked to the collecting area for linking to a drainage catheter, an outlet connection and a ventilation connection.
2. Description of the Related Art
In patients who produce too much liquor, to maintain a “healthy” internal pressure of the skull, excess liquor must be drained off. Liquor drainage systems are currently used for this. These systems usually contain, among other things, a drainage chamber (alternatively a drainage bag), in which the drained-off liquor is collected and which is suspended at a preset height above the patient's skull to set the desired internal pressure of the skull. Leading into this drainage chamber is an inlet connection, which is linked via a hose conduit to a drainage catheter (intraventricular catheter), which reaches into the patient's ventricular system to remove liquor. On the chamber there is further an outlet connection, which can be opened as required, in order to allow liquor which has collected in the chamber to flow out into a drainage bag normally linked to this connection. The drainage chamber further has a ventilation connection, through which air can escape when the drainage chamber is being filled with liquor and air can flow back when the liquor is let into the drainage bag. In order to prevent infection of the system, a filter is placed on the ventilation connection, which has a sufficiently small pore width to hold back germs.
In the known systems, hose clips and shut-off taps are used to close the inlet, the outlet and the ventilation connections or conduits. With these, a flexible hose, connected to the respective connection, is clamped or closed in such a way that passage is no longer possible. In normal operation the drainage chamber is in a holder or receptacle at a particular height above the patient's head and the inlet connection and the ventilation connection are open. The outlet connection, on the other hand, is closed.
If the patient has to change beds or has to be moved in some other way, it is regularly necessary to take the drainage chamber out of its receptacle and to place it on the patient's bed, for example, during work on the patient. Before this can be done, it is essential that the inlet connection and also the ventilation connection are closed, so that, on the one hand, no fluctuations in pressure in the liquor system in the patient's skull arise because of the change in height of the drainage chamber and, on the other hand, any contact of liquor with the filter is ruled out. The proteins or blood particles contained in the liquor may otherwise glue up or block the filter membrane, both of which may entail a risk to the patient. For if the filter is glued up air can no longer escape through it out of the drainage chamber and a counter-pressure builds up which may lead to an increase in pressure in the patient's skull with corresponding consequences. Consequences of this kind are particularly critical in children, in particular young children and babies, as patients, as they react particularly sensitively to fluctuations in pressure, owing to the smaller amount of liquor by nature. Furthermore, there may be a “siphon effect” where the chamber is emptied because the filter is glued up or closed.
Correct operation of the clamps by the care staff is therefore extremely important and a possible source of error with fatal consequences. If, as frequently provided, further connections are provided in the conduit to the drainage catheter (intraventricular catheter) for administering medicines or measuring pressure, here too three-way valves integrated in the system at these points must be correctly operated, further increasing the possibility of defective operation.